Improvement in electric railway-signals



J. S. FARMER & E. TYER.

ELECTRIC RAILWAY-SIGNAL.

No.170,540. Patent ed Nov. 30, 1875.

MPETERS, FHOTO-LITHOGRAPHER, WASHiNGTON. D Gv UNITED STATEs PATENT OFFICE,

JOHN s. FARMER, OF CANTERBURY RoAD, KILBURN, AND EDWARD TYER, OF No. 4 oLD sTREET, FINsBURY, ENGLAND.

IMPROVEMENT IN ELECTRIC RAILWAY-SIGNALS;

V Specification forming part of Letters Patent N 0. 170,540, dated November 30, 1875; application filed May 24, 1875.

To all whom it may concern:

Be it known that we, JOHN STINsoN FAR- MER, of Canterbury Road, Kilbu'rn, in the county of Middlesex, England, and EDWARD TYER, of No. 4 Old Street, Finsbury, in the county of Middlesex, England, have invented an; Improvement in Signals for Railways; and do hereby declare that the following description, taken in connection with the accompanyin g drawings, hereinafter referred to, forms a full and exact specification of the same, wherein we have set forth the nature and principles of our said improvement, by which our invention may be distinguished from others of a similar class, together with such parts as we claim-and desire to secure by Letters Patent-that is to say:

Our invention relates to combined mechanical and electrical apparatus for working and controlling the semaphore-signals of railways,

so that from one or more distant stations these signals can be kept at or set to their nalman who usually works them, and that they cannot be set to their safety attitude by the said signalman unless all the persons at the distant places agree that this may be done,

By working and controlling the signals in this manner the traffic of the railway can be conducted ,more eflectually on the block system, because by the means which we will describe a signalman at a distant station can not only apprise the signalman at the near station that the line is blocked, instructing him thereby to put his signal at danger, but can actually put the said signal to danger, or keep it at danger until the line is so far clear that the danger-signal may be taken off; and not only may the signalman at one distant station'effect this, but two or more signalmen may have it in their-power 'thus to control a signal, every one of them being enabled'to put it to or keep it at dange independently of all the others, and it being necessary that all of them should agree before the signal can be put to safety, also,

this controlling effect can be produced by our apparatus not only from signal-stations, but also from" any parts-0fthe line,so that, in caseof any such parts being blocked by accident, or for repair or other purposes, the signals commanding the traffic of such blocked parts can be worked and controlled in the manner set forth.

The apparatus which we employ for this purpose is susceptible of various modifications in its form and arrangements; but these modifications are all dependent for their action on certain general principles, which we will briefly state before we describe more particularly the methods by which we practically apply them.

At the lever, usually employed to work the signal, or on the signal-post, or in any convenient part of therods, wires, or other pulls which connect the lever to the signal, we provide a connection, which can be made or broken, so that in the one case, when the connection is made, the signal can be worked by the lever in the usualway, the signalman having it then in his power to move it to danger or to safety, as he may desire; but in the other case, when the connection is broken the lever is rendered inoperative on the signal, which, being biased by a counterweight, will rise to or remainat its danger attitude, the signalman having no power to move it to safety. This making or breaking of the connection between the signal and its lever is efi'ected by means of electricity transmitted through coils of electro-magnets, so as to cause them to attract, or, by the cessation of the electric current, to fail to attract, armatures which act upon catches, engaging them together under the one set of electrical conditions, or disengage them from each other under the other set of electrical conditions,

and the transmission or cessation of these nal is free to be worked, or whet-her, by th e action of one or more of their number, it is kept at danger. I

It may be readily understood that appara 'tus embodying these general principlescould be arranged to act either by the transmission or the cessation of electric currents. We prefer, however, in all cases, to arrange it so that the transmission of an electric current is necessary in order that the lever may be operative on the signal, the cessation of such currenthaving the effect of breaking the connection. or rendering the lever inoperative on the signal. This is the safer mode of working, because according to this mode the accidental cessation of the current can only have the effect of stopping the traffic by raising the signal to danger, or keeping it at danger. Nor does. working in this manner necessarily involve constant expenditure of electrical force, for we can so arrange the apparatus, as we will hereafter explain, that the electrical circuit is completed only at such times as the signalman may desire to lower the signal to safety. If, then, it is completed by contact made not only. at the signalstation, but also at all the other places in the circuit, the signalman will have power to lower his signal; but if at any one of these places the circuit is interrupted, the signalman will have no such power, and the signal will remain at danger, if that were its previous attitude, or it will rise to danger ifiit previously stood at safety.

Having thus stated, generally, the means which we employ to produce the desired effect, we will now describe in detail a form of apparatus whereby electricity is, according to our. invention, caused to make or break the con-' .nection between the signal and its lever, re-

ferring to the accompanying drawings and to the figures and letters marked thereon.

Figure 1 represents diagrammatically two block-stations, A and B, at some distance apart on a line of railway, with a semaphoresignal, S, near. the one station, which can be lowered to safety by a signalman at A, when the signalman at B permits it, but which can .be raised to or kept at danger by the signalman at either A or B. Fig. 2 shows, to an enlarged scale, a section of the signal'box A, with the usual signal-lever L therein, and the connections from the said lever to the sema' phore S. Fig.- 3 is a part section to a still larger scale through the frame of the point and signal-levers in the box A, showing our improved apparatus for the connection or disconnection of the lever L and the signal-pull .P, and Figs. 4 and 5 are similar sections,

showing the said apparatus in different conditions of its action. Fig. 6 is a front view of i the electrical makeand-break indicator I in thesignal-box B, by means of which the signalman there is enabled to act on the apparatus in A.Fig. 7 representing to an enlarged scale anindicating portion of the said indicator.

It will be seen from Figs. 1, 2, and 6 that an electrical wire, W, communicating with earth X at the station B, passing through the indicator I in the signal-box B, is led along the line to the apparatus in A, and, after passin g through an indicator, J, in the signal-ho): A, communicates again with earth at X. The indicator I has a knob or button, 6, by turning which the continuity of the wire W can be completed or interrupted in the usual way, a small disk, t", on the stemof the button being turned with the stem, so as to present through a hole in the case of I words such as free or locked, according as the circuit is completed or broken. A battery being placedin any convenient part of the circuit, when the signalman at B turns the button '5 so as to present the word free, thereby completing the circuit, a current of electricity passing along the wire W acts, as will presently be described, on the lever apparatus in A, and at the same time causes the small indicating-semaphore of I to stand at safety, as shown in Fig. 6. i

The indicator J is similar to I, exceptthat it has no make-and-break knob, and its small indicating-semaphore also shows safety when the circuit is completed. When, on the other hand, the signalman at B turns the knob i. so as to present locked at thehole of the indicator I, then, the electrical circuit being broken, there is no action on the lever apparatusin A, and the small semaphores in I and J take the danger attitude.

Besides the one make-and-brcak indicator I in the signal-box B, there may be others situated at different parts of the circuit W, and it is to be understood that the circuit can be broken at any one of those, and that there is, therefore, electrical action on the lever apparatus in A only in the case when the current is completed at all such indicators. Moreover,

should the battery-power. fail, or thewire W be broken, then also the electrical action on the lever apparatus in A will cease. Referring, now, to Figs. 3, 4, and5, in which the 'same letters are employed. to indicate like which, on being drawn upward, has the effect of lowering the selnaphore-arm S to its. safety attitude, but which, when it is. slacke d down, permits the semaphore to be raised by a counter-weight to its danger attitude.

Above the levers G and Dispivoted a third lever, E, which hason it an iron hammer-head, 0. An electro-magnet, M, is fixed in such a position that when the lever. E is raised its hammer-head e bears against the poles of the magnet M as an armature, the weight of the lever and its head being so disposed withr efe erence to its pivot that when it is raised, as shown in Figs. 3 amid, the center of gravity is nearly but not quite vertically over the pivot, and consequently a very moderate attractive force of the magnet M servesto reimam s tain the lever E in its upright attitude. If, however, there should be no such attractive force, then the lever E will fall to the position shown in Fig. 5, its head 0 striking the tail of the catch 0. This catch is so made and hung that when left free it engages with the nose of the lever D, and in that case, when the lever L is pulled over, as shown in Fig. 4, raising the lever O, the lever D is raised with it, and the pull P being drawn upward, the semaphore S is lowered to safety. When, however, the head 6 bears on the tail of the catch 0, disengaging it from the nose of D, as shown in Fig. 5, then the levers L and C may be moved without afl'ect-ing D, which remains down, the pull P then permitting the semaphore S to take and remain in its danger attitude. On the lever 0 there is another balanced catch, f, having at its upper end a gab, that engages with a pin, a, on the lever E. This pin has a certain freedom of motion in an oblique slot, being kept up toward one end of it by a spring, 0.

When the levers O D E are all down, as in Fig. 5, then the catch f is engaged under the pin n, and on the lever L being pulled over, so as to raise O, the lever E is raised through a much greater angle, so that its head 6 reaches the poles of the magnet M, a stop, N, being provided in the framing to prevent E from goiu g too far.

From the construction which we have described it will now be understood that as long as the electro-magnet E, the coils of which are in the circuit of W, is rendered active by a current of electricity, its attraction holds to its poles the head 6, and the levers G and D being then engaged together by the catch 0, the semaphore S can be raised or' lowered by the movement of the lever L but as soon as the attraction of the magnet M ceases by the cessation of the electrical current through its coils, then ewill drop if it has been raised, or will not be held up, as in Figs. 3 and 4, but will fall, as in Fig. 5, disengaging or keeping disengaged the catch a from the lever D, in which case the semaphore S rises to or remains at danger. This is the result of interrupting the electrical current anywhere in its circuit, taking it out of the power of the signalman atAto lower the semaphore by means of his lever L, or, if it should have been lowered by the lever L, disconnecting it therefrom, so that it is immediately raised by its counter-weight to *danger. As, in order to secure this result, it would be necessary to maintain an electrical current constantly in the wire W, except when the circuit is casually interrupted, there would be an unnecessary expenditure of electrical force during the ordinary working of the line, such force being maintained even when there may be no occasion to lower the signal.

In order to economize the expenditure of electrical force we connect the wire W not directly to earth from the coils of the magnet M, but through an insulated spring-contact, T, whereby the circuit is completed only when the lever E is raised, as in Figs. 3 and 4, a projection, e, on the said lever being then brought to bear on the spring T, so as to make contact. Thus it is only when the lever L is moved so as to lift the lever E that the elect trical force is passed through the circuit. At all other times, while E remainsdown, the circuit is broken at T, even when it is completed at all other parts of the line.

Having thus described the nature of the said invention, and the best means we know of carrying it into practical effect, we hereby declare that we do not claim any mode of applying electricity to give movement to a railand wire W, as and for the purposes described.

v 2. The combination, for effecting the connection or disconnection of the lever and signal, of the levers O D E and catches c and f with the electro-magnet M, and wire W, and makeand-break indicator 1, substantially as herein described in reference to the accompanying drawings.

The combination of the spring-contact T with the lever E, for the purpose of economizin g the electrical force, substantially as herein described. I

In testimony whereof we have signed our names to this specification in the presence of two subscribing witnesses this 10th day of May, 1875.

. JNO. S. FARMER. EDW. TYER. Witnesses:

. M10. P. M. MILLARD,

J. B. WYNN. 

